Process for tempering light alloys



Patented Nov. 17, 1925.

UNITED STATES GLEN LENARDO WILLIAMS, OF DETROIT, MICHIGAN.

PROCESS FOR TEMPERING LIGHT ALLOYS.

No Drawing.

To all whom it may concern:

LIAMS,'2L citizen of the United States of America, residing in the city of Detroit, in the county of \Vay'ne, in the State of Michigan, have invented certain new and useful Improvements in a Process for Tempering Light Alloys, of which the following is a specification.

This invention relates to a process of treating the surface of light alloys such as duralumin, magnelium, williamite, electron and similar compounds, these trade names being given to alloys of aluminum, magnesium, or glucinum.

The light alloy is annealed and cooled slowly. lVhen the metal is cooled, it is rolled, pressed, or mounted in any form de sired. The articles thus prepared'are placed in a steam jacketed tank which may be made of copper, iron, nickel, or other metal, the tank acting as the positive pole of an elec tric circuit of the low voltage ordinarily used for plating. WVithin the tank is placed 3 a solution of metal salts, such as copper cyanide, or nickel-ammonium sulphate, or silver cyanide, or iron chloride, or magnesium sulphate, one or more salts being used in the solution. With the articles in the solution connected to the negative pole of the circuit, the solution is cooked by boiling. The temperature is gradually lowered and after a proper time, ibe articles are taken out and cooled rapidly. In some cases, even an ice water bath is used to produce a quick action of tempering.

\Vhen articles made of a light alloy are boiled in a solutionas described while a low voltage electric current is passed, the articles acting as the cathode, the metals in the plat-' ing solution are deposited in the metallic surface of the alloy, the alloy taking up enough of the other metal to make the surface hard while the alloy is left in its old Application filed May 8, 1922. Serial No. 559,284.

0 1 cond1t1on inside, 1n a manner similar to the Be 1t known that I, GLEN LENARDO WIL- case hardening of steel alloys.

Salts of any metals may be used which will alloy with aluminum, glucinum, or magnesium, and the strength of the solution may vary from 30 B. even to 1 B. The articles are taken from the bath and cooled or quenched with clean cold Water before a covering is formed, the metal or metals absorbed into the surface of the alloy causing the hardening.

I claim:

1. The process of treating light'metal alloys which consists in boiling a solution of a metallic salt in a metal tank, immersing the alloy therein, and electrolyzing said solution with the alloy as cathode and the tank as the anode. 1

2. The process of treating light metal alloys which consists in boiling the solution of a salt of a metal heavier than the alloy with the alloy immersed in the solution duringthe boiling operation, electrolyzing the solution with a current of low voltage and with the light alloy acting as the cathode and the heavier metal as an anode, and then immersing the alloy in cold water, whereby a hard metal surface is formed upon the softer metal alloy.

3. An electrolytic method for treating light alloys which consists in immersing the alloy in a hot solution of a salt of a heavier metal, subjecting the solution while heated to an'electrolyzing current with the alloy active as the cathode until the alloy surface has taken up metal from the solution, and then quenching the alloy in cold water.

In testimony whereof I hereby aflix my signature.

Signed on the 25th day of April, 1922, in the city of Detroit, in the county of \Vayne, in the State, of Michigan.

GLEN LEuAnDo WILLIAMS. [a 8. 

